Thulium (Tm)
Thulium (Tm) is element 69 of the periodic table, a lanthanide in period 6, in the f-block. Its standard atomic weight is 168.934219, so one mole of thulium atoms has a mass of 168.934219 g. At room temperature it is a solid; it melts at 1544.85 °C and boils at 1949.85 °C.
| Atomic number | 69 |
|---|---|
| Symbol | Tm |
| Standard atomic weight | 168.934219 |
| Molar mass | 168.934219 g/mol |
| Category | Lanthanide |
| Group | f-block (lanthanide series) |
| Period | 6 |
| Block | f-block |
| Electron configuration | [Xe] 6s2 4f13 |
| Oxidation states | +3 |
| Electronegativity (Pauling) | 1.25 |
| Atomic radius (van der Waals) | 227 pm |
| First ionisation energy | 6.184 eV (596.7 kJ/mol) |
| Electron affinity | — |
| State at room temperature | Solid |
| Melting point | 1818 K (1544.85 °C) |
| Boiling point | 2223 K (1949.85 °C) |
| Density | 9.32 g/cm³ |
| Discovered | 1879 |
Lanthanides
La · LanthanumCe · CeriumPr · PraseodymiumNd · NeodymiumPm · PromethiumSm · SamariumEu · EuropiumGd · GadoliniumTb · TerbiumDy · DysprosiumHo · HolmiumEr · ErbiumYb · Ytterbium
Calculate with Thulium
Atomic weight: IUPAC CIAAW standard atomic weight. Other properties: PubChem (U.S. National Library of Medicine, public domain). Values such as melting point and radius depend on how they were measured; check a data book for precise work.